The vast majority of cases of harlequin ichthyosis have biallelic mutations in the lipid transporter gene ABCA12 (Akiyama, 2014), but this previous report (Stewart et al., 2001) and our current findings in two further subjects with harlequin ichthyosis identify KDSR as a possible additional candidate gene for non-ABCA12 harlequin ichthyosis. This evidence concerns the gene KDSR and Harlequin ichthyosis.